cubo 12

Cubo15 wrote: Hi Jim,

If I understand correctly, you want to build Cubo 12 with a minimum change to both the horn and chamber volume, utilising 18 mm material?

In that case the overal height should increase 3 mm for every panel it meets from bottom to top (5 panels) = 46.5 cm.
The overall depth (3 panels) = 48.9 cm. The overall width (2 panels, ignoring the bracing) = 45.6 cm

Top panel/ground panel; 48.9 x 42 cm (I ussually make these panels few mm longer and cut them to size after the build)
Side panel left/right; 48.9 x 42 cm (I ussually make these panels few mm longer and cut them to size after the build)
Rear panel; 42 x 42 cm
Front panel; 18.4 x 42 cm
Baffle; 32.45 x 42 cm
First horn panel; 30.7 x 42 cm
Second (angled) horn panel; 13.95 cm (same)
All Bracing: + 3 mm or the same

Tell me, if i have made a mistake.


@Kentech: Could you send an e-mail to questionsaboutcuboatgmaildotcom ?
Perhaps I’ve an interesting design-mod for you.

Best regards

Cubo

am looking at side panel u have 48.9 x 42cm but that does not add up to 48.9 x 46.5 cm

Top panel/ground panel; 48.9 x 42 cm (I ussually make these panels few mm longer and cut them to size after the build)
Side panel left/right; 48.9 x 42 cm (I ussually make these panels few mm longer and cut them to size after the build)

Either the top/ground panels or the side panels should be 48.9 x 46.5 cm, whilst the other two remain 48.9 x 42 cm.

Best regards

Cubo

Cubo15 wrote: Practically a 33 cm wide cabinet made from 15 mm material, often means the 12" driver won't fit unless extra space is created "into the walls" (i.e. with a router).

Other then that, I will look into it more closely, perhaps I will be able to make it mutually beneficial.

Best regards

Cubo

how about a 37 to 37.4cm wide cabinet made from 18mm material so sad we cant get 15mm plywood in the us :oops:

A bit of a 'off the wall' question, but how might a pair of 12" ATC PA-75 314 LCR drivers (spec sheet attached) perform in isobaric mode (clamshell) in a Cubo12; or might this work better in the Cubo 15?
Thinking primarily along the lines of reduced distortion and perhaps 'reclaming' some SPL from the box design....
Mik

how about a 37 to 37.4cm wide cabinet made from 18mm material

Making Cubo 12 that width would loose you the lowest region.

Cubo 12 Mod (52.5 x 35 x 52.5 cm, HxWxD from 15 mm material). Making Cubo 12 Mod that width should do it.

Best regards

Cubo

I suppose you're talking about the Bass-LCR?

Isobaric mounting would halve Vas, meaning effciency would drop 3 dB in comparison with a single driver. Two drivers in two cabinets would have 6 dB higher sensitivty (if stacked) in comparison with a isobaric mounted pair in a single cabinet. In fact i woud rather use a single LCR in Cubo 12 then an isobaric mounted pair.

A push-pull design could be done for a pair. It would act as a "normal" double Cubo 12 but with reduced 2nd order harmonics. You would need to re-allign the drivers to minimize differences in the chamber and horn volume near the mouth.

If you need any help with that, just let me know through questionsaboutcuboatgmaildotcom.

Best regards

Cubo

Yes, Bass LCR's - have 4 of them looking for a suitable box or two!

Thanks, will be in touch on this as there is a 'space' issue which means 4 boxes wouldn't really fit!
SPL isn't really the more important thing as only have to match 98dB/1W/1m from the Mids with about 200W max input in a relatively small space, but the lower distortion looks very interesting.

How would they perform as singles in terms of useful bandwidth as opposed to a 'double' other than the expected 3dB of reduced SPL?


Mik

The main feature of isobaric loading in a typical vented or closed box allignment is that the "new" driver (in an enclosure of volume X)gives the same performance as a single driver in an enclosure that is double that volume (so 2 times X). In this case the rear chamber is a smaller part of the whole and the effectiveness isn't as great per cabinet volume as it is with normal reflex or closed allignments. Also, the second driver takes away some of the rear chamber volume by default.

I suspect the frequency response to be similar or up to 5 - 6 Hz lower then a single driver in a single enclosure, in the latter case at the totall cost of 5 dB, of which 3 db due to halving the Vas.

Note: Not accounted for the air mass trapped between the cones.

How large could a single cabinet containing two drivers be (maximum measurements)?. A double version can be truncated.

Best regards

Cubo

Hi guys.

I wanted to try some hybrid for home usage and some outdoor fun, so after some nice help from Cubo, I tried Cubo12mod. I have B&C 12PS100 for it.
My friend and me ompared it against some nice and sensitive 18" bassreflex sub he made. It really can equal this subs on 60Hz and up. That is cool for that size. During changing the connection between 12" and 18", I sometimes forgot which one did i connect... But lower response is poor. We could not manage to get any 40Hz-ish sound (guitar, drum kick) from this bin even after really brutal eq. I rebuilt it to 45l bassreflex cab and will see what happens with the bass. Feel bad for loosing several decibels on sensitivity, but no way.
I cannot reccommend this cab for home usage. If you want go loud in small size, that is the bin for you.

Does anyone have the plans for CUBO10 ? I want to builtan mid-top and for the low part i want to use 2 x Cubo10 mouth to mouth crossed somewhere at 150-200hz and from there a mid andhigh should do the job. Maybe the cross point will be higher, i don;t know untill i will built one.
Mr. Cubo or somebody can u help please ?